The present invention relates to a computer system and in particular to a user interface for a computer system which is useful with application software, for example, spread sheets, data bases, graphics, games and communication and most preferably with word processing and computer aided design software.
The use of computer systems, while becoming an increasingly essential part of many businesses, is still limited by the problems associated with the user interface. These problems include the lack of speed with which the user can input data and commands, the discomfort associated with working at a computer and the lack of acceptance of the interface due to the complex commands that must be used to carry out computer operations.
The most common interface device for computer systems, the keyboard, is an awkward and unfamiliar device to many, especially executives, and is ill suited to all tasks except text or data entry.
Other interface devices such as mice, touch screens, light pens, digitizers and touch pads have significant drawbacks that are addressed by the present invention.
An example of a keyboard interface work station can be seen in U.S. Pat. No. 4,562,482, an example of a touch screen input device can be seen from U.S. Pat. No. 4,313,109 and an example of a digitizer graphics input device can be seen in U.S. Pat. No. 4,550,250.
These disadvantages have apparently not gone unnoticed and are the subject of work in the prior art. For example, U.S. Pat. No. 4,190,833 teaches the use of an alpha numeric terminal comprising a text generator and a display unit consisting of a cathode ray tube screen arranged to display a plurality of lines of text on half of the screen and a set of alpha numeric characters on the other half of the screen which can be selected by the use of a light pen.
While this system eliminates the need for a keyboard, it substantially reduces the area of the screen which can be used to display text and still necessitates the use of a separate device for moving the cursor to indicate a desired location in the text on the screen.
U.S. Pat. No. 4,475,239 apparently recognized that the most comfortable way of editing and processing a printed text is to work on the text itself. In this apparatus, a printed piece of paper is placed in a digitizer field so that portions of the printed text on the paper can be edited by the user.
The disadvantage of this system is that after all of the text editing changes are made, the changes are fed into a computer so that the memory thereof can be updated and the text is again printed out in final form to enable the user to see the result of the changes. However, if the user desires to enter new text information while text editing, this must be still done by a keyboard. Moreover, there is no real time display, since the results of the changes are not displayed until after all of the changes have been entered and the text printed out, and there is no way of knowing if the changes that have been requested are correct until sometime thereafter.
In U.S. Pat. No. 4,430,526 an interactive graphics transmission system is disclosed wherein a light pen is used to indicate writing and erasing of a graphic image within a specific image area which is then transmitted via video camera to a graphics display terminal. Since the light pen is not used with the display screen itself, it is no different than a mouse or other input device, with the exception that the image area on which it is operating, is transmitted via video for video teleconferencing.